From patchwork Tue May 5 02:44:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bhaumik Bhatt X-Patchwork-Id: 189285 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9380C4725B for ; Tue, 5 May 2020 02:45:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B63B420707 for ; Tue, 5 May 2020 02:45:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="V5g/9TCf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728217AbgEECpB (ORCPT ); Mon, 4 May 2020 22:45:01 -0400 Received: from mail26.static.mailgun.info ([104.130.122.26]:44379 "EHLO mail26.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728280AbgEECoj (ORCPT ); Mon, 4 May 2020 22:44:39 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588646678; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=L9nUz4QcIV4087LWk9ngQ8J3kGqbHnK2hICsHkNIRUU=; b=V5g/9TCfRm9ItV7S05wSyPVNHA7UUq46ui78Gv0NBKv7NLhzAUIpIMJ/mv3Nv63tt0MJe3kM ZhefU6U9xiwEMMY9YjloT26zkMgY6r6OA+3G3Wju27f64T4PiR1yaX7aRB+oCU6r9ykGeBT2 RAu0vPY0zvZSvqkrdqtEofThK34= X-Mailgun-Sending-Ip: 104.130.122.26 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5eb0d313.7fdbc3075d50-smtp-out-n03; Tue, 05 May 2020 02:44:35 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id A3395C4478F; Tue, 5 May 2020 02:44:35 +0000 (UTC) Received: from bbhatt-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: bbhatt) by smtp.codeaurora.org (Postfix) with ESMTPSA id 12393C4478C; Tue, 5 May 2020 02:44:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 12393C4478C Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=bbhatt@codeaurora.org From: Bhaumik Bhatt To: mani@kernel.org Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, hemantk@codeaurora.org, jhugo@codeaurora.org, Bhaumik Bhatt Subject: [PATCH v5 4/8] bus: mhi: core: Read transfer length from an event properly Date: Mon, 4 May 2020 19:44:18 -0700 Message-Id: <1588646662-25785-5-git-send-email-bbhatt@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1588646662-25785-1-git-send-email-bbhatt@codeaurora.org> References: <1588646662-25785-1-git-send-email-bbhatt@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org From: Hemant Kumar When MHI Driver receives an EOT event, it reads xfer_len from the event in the last TRE. The value is under control of the MHI device and never validated by Host MHI driver. The value should never be larger than the real size of the buffer but a malicious device can set the value 0xFFFF as maximum. This causes driver to memory overflow (both read or write). Fix this issue by reading minimum of transfer length from event and the buffer length provided. Signed-off-by: Hemant Kumar Signed-off-by: Bhaumik Bhatt Reviewed-by: Jeffrey Hugo --- drivers/bus/mhi/core/main.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index e60ab21..159732e 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -514,7 +514,10 @@ static int parse_xfer_event(struct mhi_controller *mhi_cntrl, mhi_cntrl->unmap_single(mhi_cntrl, buf_info); result.buf_addr = buf_info->cb_buf; - result.bytes_xferd = xfer_len; + + /* truncate to buf len if xfer_len is larger */ + result.bytes_xferd = + min_t(u16, xfer_len, buf_info->len); mhi_del_ring_element(mhi_cntrl, buf_ring); mhi_del_ring_element(mhi_cntrl, tre_ring); local_rp = tre_ring->rp; @@ -598,7 +601,9 @@ static int parse_rsc_event(struct mhi_controller *mhi_cntrl, result.transaction_status = (ev_code == MHI_EV_CC_OVERFLOW) ? -EOVERFLOW : 0; - result.bytes_xferd = xfer_len; + + /* truncate to buf len if xfer_len is larger */ + result.bytes_xferd = min_t(u16, xfer_len, buf_info->len); result.buf_addr = buf_info->cb_buf; result.dir = mhi_chan->dir;